Good points! And even more significant may be the energy needed to accelerate back to 50 MPH after each of those wasteful stops.

For my own purposes, I want to see if it's possible to achieve a sort of "over unity" by driving my electric vehicle uphill, unloaded, and then come back down with a heavy load of firewood, and use Regenerative Braking to recoup what was expended and even register a net gain!

Ah, but that's not over unity. How much power did it take to grow the rice that you fed your peasants to carry the wood up that hill?

Actually it's solar and wind power, since the wind blew the seeds there and the sun provided power to make the trees grow. And I had to use a lot of power to cut the trees into logs and split them. I could possibly use the tractor's batteries for an electric chainsaw, but that would greatly skew the results. Then again I could use the wood with a steam power plant on the tractor, to avoid using fossil fuels.

Also, all sources of power on the earth are ultimately derived from Solar Power which in turn is nuclear fusion. And nuclear fusion in stars originally formed radioactive elements that we use in fission reactors.